It is often desirable, and sometimes required, to decontaminate groundwater by pumping contaminants from a well. This is possible if the contaminant is a separate or floating layer on or within the groundwater. If the contaminant is a hydrocarbon, an added benefit is that the fluid may be recycled for reuse. Pumps used to remove a floating liquid layer to an elevated location are disclosed in U.S. Pat. Nos. 5,147,184; 3,669,275; 4,243,529; 4,273,650; 4,663,037; 4,872,994; and 4,998,585.
A problem with existing designs is that they often require numerous component parts, including moving parts, and therefore tend to be complex. Such products often use stationary inlets in conjunction with hydrophobic screens, floating inlets attached to coils, or more complex inlet structures used in conjunction with sensors and pneumatic cylinders. Stationary inlets may be mispositioned out of the product when the water level drops, or they can be completely submerged under the water if the level raises to an unacceptably high degree. Hydrophobic screens can be easily fouled and plugged, and floating inlets can hang up for various reasons. Coils may also be plugged by discuss hydrocarbons, such as spent motor oil and other thicker fluids.
The need remains, therefore, for a submersible pump that may be used for simple pumping operations, including fluid separation. Ideally, such a pump would be able to handle a large water table fluctuation range, as well as viscous hydrocarbon products.